Davis had pleaded not guilty of lethally injecting two elderly residents of the SummitCare Wallsend aged care facility near Newcastle — Gwen Fowler and Ryan Kelly — on consecutive days in October, 2013.

He also pleaded not guilty to attempting to murder another resident, Audrey Manuel, by the same means.

The Crown case was purely circumstantial, but prosecutor Lee Carr argued throughout the case that Davis knew all three victims, was at the nursing home when all three were injected with insulin and had a record of administering insulin to patients against the facility’s protocol.

Key to the Crown case was a series of mobile phone text messages Davis sent to two friends, seemingly predicting who would be next to die, despite the fact all three victims were relatively healthy at the time.

During the trial, defence barrister Chris Watson told the court lax security procedures at SummitCare Wallsend at the time meant there was little monitoring of people coming and going from the facility’s residential wards.

“Our case, simply put, is that we don’t know who did it, but it wasn’t us,” Mr Watson told the trial.

But Justice Hulme rejected that assertion.

Outside court, following the decision, Mr Lee said the families were pleased with the verdict.

“From the family point of view, I’m thrilled … it’s closure for them,” he said.

“I think they’re just happy to have closure and have a reason for the loss of their loved ones.”

He also praised police work in bringing Davis to justice.

“It was an excellent, excellent police investigation — they did an excellent job over a very long period of time,” he said.